Filtering induction device

Abstract

A filtering induction device is provided to improve the filter effect via the increase of an insertion loss resulting from stray capacitance. The induction device includes at least one core structure, and first and second flat coils that interlacing with each other. The first flat coil is used as an inductor, and the second flat coil is used as an electrode belonging to a capacitor formed between the circles of the first flat coil.

1. A filtering induction device, comprising:
 a first coil having a plurality of circles, wherein the first coil is used as an inductor and is covered wit an isolation material; 
 a second coil having a plurality of circles, wherein the second coil has one terminal grounded and is interlaced with the plurality of circles of the first coil; and 
 a core structure coupled to the first and second coils. 
 
   
   
     2. The filtering induction device of  claim 1 , wherein the first coil is a flat coil. 
   
   
     3. The filtering induction device of  claim 1 , wherein the second coil is a flat coil. 
   
   
     4. The filtering induction device of  claim 1 , wherein the core structure is further comprised of:
 a core base adapted to contain the first and second coils; and 
 a core cover disposed on the core base. 
 
   
   
     5. The filtering induction device of  claim 4 , wherein the core base is provided with at least one opening on a sidewall thereof, via which the first and second coils extend out from the core base. 
   
   
     6. A filtering induction device, comprising:
 a first coil having a plurality of continued circles, wherein the first coil is used as an inductor and is covered with an isolation material; 
 a second coil having a plurality of continued circles interlacing with the plurality of circles of the first coil; and 
 a core structure coupled to the first and second coils. 
 
   
   
     7. The filtering induction device of  claim 6 , wherein the first coil is a flat coil. 
   
   
     8. The filtering induction device of  claim 6 , wherein the second coil is a flat coil. 
   
   
     9. The filtering induction device of  claim 6 , wherein the core structure is further comprised of:
 a core base adapted to contain the first and second coils; and 
 a core cover disposed on the core base. 
 
   
   
     10. The filtering induction device of  claim 9 , wherein the core base is provided with at least one opening on a sidewall thereof, via which the first and second coils extend out from the core base. 
   
   
     11. The filtering induction device of  claim 6 , wherein a terminal of the second coil is grounded.